Mutter
Definition 1 of 3
Pro Tip 1/3
Expressing Worry
Often used when the speaker is preoccupied or anxious about an issue. Pacing the room, she muttered about the test results.
Pro Tip 2/3
Subdued Complaining
Indicates a speaker's dissatisfaction without directly confronting the issue. He muttered about the cold coffee, but drank it anyway.
Pro Tip 3/3
Private Utterance
Used for speaking to oneself or in such a way that others are not meant to hear. He constantly muttered to himself while he worked on the complicated problem.